docs: def segment_midpoints(neurites, neurite_type=NeuriteType.all):
      '''Return a list of segment mid-points in a collection of neurites'''
      def _seg_midpoint(sec):
          '''Return the mid-points of segments in a section'''
          pts = sec.points[:, COLS.XYZ]
          return np.divide(np.add(pts[:-1], pts[1:]), 2.0)
  
      return map_segments(_seg_midpoint, neurites, neurite_type)